This invention relates to the evaluation or testing of various substances placed in small cylindrical containers, which may be regarded as one form of cuvet. Such containers are well known in the medical and biological field, and are frequently made of glass or plastic tubes of such small diameter that a liquid to be tested is drawn into the tube by capillary action. A typical material frequently tested is blood. The evaluation tests to be made on blood or other substances frequently include a separation of the ingredients or components of the liquid being tested, by subjecting the liquid to centrifugal force, and subsequent measurement of the separated components.
An object of the present invention is to provide a relatively simple structure which can be used without difficulty and rapidly for clamping the containers in the appliance, and which also guarantees a firm sealing of the containers in the rotor even at high speeds of rotation.
This object is well fulfilled by apparatus according to the invention, a preferred embodiment of which is herein disclosed as an example.